Muffle-furnace.



No. 874.452. PATENTED DEG. 24, 1907. E. L. STINE. MUFFLB PURNAGB. APPLIUA'TION FILED M4Y'23, 1906.

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E. L. STINB.

MUPFLB PURNAGE.

APPLICATION FILED MAY 23, 1906.

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l 5.7 gov/VM] No. 874,452. PATENTED DEG. 24, 1907.

E. L. STINE.

MUFFLE FURNACE.

ArPLIoATIoN FILED MAY z3, 190sA s SHEETS-SHEET s.

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i, @aff 7740877095665- Uivriiii) sTArEsPATENT OFFICE.

EDWARD L. STINE, OF BUFFALO, NEW YORK,

ASSIGNOR THE REPUBLIC METALWARE COMPANY, OF BUFFALO, NEW YORK, ACORPORATION OF NEW YORK.

MU FFLE-FURNACE To all whom 'it may concern.'

'Be it known that l, EDWARD L. STiNE, a citizen of the United States,residing at `Buffalo, in the county of Erie and State of New York, haveinventedv a new and useful Improvement in Muflle-Furnaces, of which thefollowing is a specification.

This invention relates more particularly to the muiile furnaces employedfor baking enameled or glazed kitchen utensils and other articles havinga similar coating. v

` Oneof the objects of my invention is to improve the construction ofthe muffley with a view of rendering its walls highly conductive and atthe saine timeincreasing their strength, in order to prevent .warping ofthe same under'the intense heat to which they are subjected..

p The invention has the further object to provide the furnace withan-improved arrangement of air iues for supplying heated air to the iirebox to promote combustion.

'In the accompanying drawings consisting 'of' 3-sheets: Figure 1 i's asectional perspective view of 'a furnace embodying the invention. Fig. 2is a central longitudinal section thereof.` Fig. 3 isa horizontalsection in line 3-3, Fig. 4. Fig. 4 is a transverse section. in line 44, Fig. `2. Fig. 5 is an enlarged perspective view of one of therefractory muffle-blocks or bricks. Fig. 6 is a longitudinal section ofthe same. A

Similar letters of reference indicate corresponding parts throughout theseveral views. A is. the usual fire-box or combustion chamber, and B thecustomary longitudinal cold airlines arranged in the lower portions I ofits side walls. As shown by dotted lines l and extend nearly to thefront end thereof,`

in Fig. 2, these flues communicate with the atmosphere at the rear endof the furnace Specication of Letters Patent. Application filed May 23,1906. Serial No. 318,412.

vwalls or masonry ofthe furnace.

l end of the furnace, as shown in Fig. 3.

mainor longitudinal portions are in prox- Patented Dec. 24, 1907.

out the length thereof, the same being closed at the rear end of thefurnace and its pposite open end being normally closed by the usualsliding door Dl, Figs. Zand 3.

E is the exit flue or passage for the products of combustion arrangedbetween the sides and top of the inuffle and the inclosing This fluecommunicates with opposite sides of the coinbustion chamber by a seriesof transverse v passages F located below the bed "or bottom of theinuflle while at its upper rear end it communicateswith the customarychimney flue G.

H, H indicate hot air ilues or passages for supplying heated air to thefire box to promote combustion. These flues extend lengthwise throughthe lside wallsof the furnace from'its front end nearly to its rear end,as

shown in Fig. 3, thence inwardly adjacent to the closed rear end of themufHe nearly to the center thereof, thence downwardly to a point belowthe bottom of the muffle, as shown by dotted lines in Figs. 2 and 4, andthence foi'- wardly into the upper rear portion of .the combustionchamber. The inlet ends of the flues H open into the atmosphere at the,rmt eir iinity to the hot exit flue E, so that'the cold air in passinglthrough the same becomes highly heated by the time it reaches thecombustion chamber and in this condition-commingles with the-.gasestherein, greatly. promoting combustion and producing a high temperature.Owing to the complete combustion thus obtained, slack coal may be burnedin the furnace with a natural draft.

The side walls and the arch of the muffle 'Q i are constructed of blocksor bricks d of refractory material, as fire-clay, laid incourses likeordinary bricks. The blocks are preferably provided with tongues ol1 andgrooves d2 for interlocking them, those shown in the drawings (Figs. 5and 6) having tongues at one end and one side and grooves in theremaining end and side. Heretofore, the iniillle has been built np ofcomparatively thin and long'blocks or slabs, but this construction isobjectionable becauseof the narrow contact or supporting edges ofcontiguous s'labs. and their consequent liability to warp and becomedisplaced in a short time by constantA exposure to the intense heat,

amaca To overcome this obj'ection, l employ com-` i, with the atmosphereand leading to the comparatively thick blocks, as shown, which afbustionchamber, substantially as set forth. 'ford a wide base or bearingsurface for the 2. In a mule furnace, the combination of same. ln orderto permit the necessary l the combustion chamber, a mufiie arrangedconduction or penetration of the heat from l above said chamberlengthwise of the furthe exit flue into the mutlie, each block is naceand separated from the furnace-Walls provided with one or more recesses,cavities by an intervening longitudinal exit-flue for or depressions dextending inwardly from its face nearly to its back. This construelclosed at its top and sides to isolate its intion, while producing astrong and stable l terior from said flue, and hot air'flues armuftlewhich elfectually resists warping of ranged in the side walls of thefurnace lengththe blocks, renders the backs of the blocks wise of themuflle and adjacent to said exit sulliciently thin to allow the heat topass through them. Satisfactory results have been obtained by` the useof blocks nine inches long, four inches wide and four inches thick.

l indicates the horizontal series of blocks o r kickers which span theexit flue E on lopposite sides of the muflle and'serve to retard theescape of the products of combustion into the chimney. These blocks forma tight partition between the upper ,and lower f portions'of the llueexcept at the front end of ,j the furnace, where a number of openings orpassages i are formed for the escape of the products of combustion, asshown 1n Fig. 3. 'llie outer ends of these kickers are preferablyembedded in the side walls of the furnace, while their innei endsrest'upon ledges or supports y' formed on ory carried by the ad L jacentcourses of blocks, as shown in Figs. 1 & 1l. By this construction thekickers are iirmly supported at their inner as Well as their outer endsand eli'ectually prevented from sagging out of place and allowing theheat to escape too freelyl and ultimately,

` droppingintothe passages F and clogging l cesses terminating short oftheir backs, the

" closed backs of the blocks forming the inner the same.

l claim as my invent-ion: l. In a muflie furnace, the combination of thecombustion chamber, a mulle arranged above said chamber lengthwise ofthe furnace and separated from the furnacawalls by an interveninglongitudinal exit-flue for the products of combustion, and a hot airflue arranged in the side wall of the furnace lengthwise of the muflieand adjacent to said exit-flue, said hot air flue communicating i flue,said hot air flues extending from the front end of the furnacethroughout Vthe l length of the exit flue and communicating at theirrear ends with the combustion chamber, substantially'as set forth.

3. In a mufle-furnace, the combination of the combustion chamber, amufle arranged above said chamber lengthwise of the furnace andseparated from the furnace-walls by an intervening exit flue for theproducts l of combustion, and longitudinal'hot air iues arranged in theside walls of the furnace ad i jacent to said exit iiue and extendingfrom l the front end of the furnace throughout the length of said exit|line and thence inwardly g and downwardly adjacent to the closed rearend of the mutlie and into the combustion chamber, substantiallyas setforth. 4. In a muflie furnace, the combination of j the combustionchamber, and a muflie sepal rated from the furnace-Walls by an intervenling flue for the products of combustion, the walls of the muttle beingconstructed of coml paratively thick refractory bloc-ks laid in lcourses and provided in their inner sides which face the interior of themuiiie with rewall of said flue' and preventing communica i tion betweenthe same and the muffle, sub- 1 stantially as set forth. l Witness myhand this Sthdayof May, 1906. l y i EDWARD L. STINE. s i Witnesses:

C. F. GEYER, E. M. GRAHAM.

the products of combustion,` the munie being I

